Higher Physics Lab Light & Optics



Exp-1: To demonstrate the kerr effect in nitrobenzene solution.
Exp-2:To observe brightness on detector depending on voltage applied.
Exp-3: To determine half wave voltage for blue light.
Exp-4:To determine kerr constant.

  • All electrical connections are made using 4mm safety sockets and plugs
  • Saddle can hold rod from 8 to 15mm.
  • Heavy, rigid and stable Triangular Optical bench (made of Al extrusion).
  • Height and level adjustment screws (made of SS)
  • Analyser/Polayser with 0 ± 90° graduation.
  • Electrode with 4mm safety socket (for 6 kV).
  • High voltage DC power supply with thermal safety switch.
  • Polarization of light
  • Bire-fringent
  • Kerr cell
  • Opto-electro effect

Principle and Working :
Certain materials under the influence of strong electric field become doubly refractive. The effect known as Kerr effect can be observed in this experiment with nitrobenzene solution.
In the present setup, a small glass container mounted with plate capacitor is filled with liquid. The container is kept between two filters placed at 90°. There will be dark field of view on screen initially but after applying electric field, the field of view brightens, because the light beam becomes elliptically polarised when passed through the birefringent liquid.

Safety Note:
Nitrobenzene is poisonous and may have carcinogenic effect:
1. By inhalation
2. By contact with skin
3. By swallowing


Cat No. Item Name SK019
SLA19 Kerr Cell with electrode 1
SL801 Polarizer / Analyzer 2
SW840 Halogen light source 1
C0526 Object screen 1
SE1005 High voltage power supply 1
SE080 Power supply 1
SL223 Prism table 1
SL214 Optical bench triangular 1
SL754 Convex lens in holder 1
SLA65 Blue filters 1
SN204 Flexible plug lead,50cm (red & black) 1
SN201 Flexible plug lead,100cm (yellow) 1
SN201 Flexible plug lead,100cm (red & black) 1
Sl436 Transverse slider 1
Silicon detector 1
Digital Multi meter 1
Power cord 2
Fixed slider 4
Fixed slider (large) 1